Axial piston type impulse tool



Oct. 19, 1965 J. s. VAUGHN 3,212,295

AXIAL PISTON TYPE IMPULSE TOOL Original Filed Dec. 12, 1962 4Sheets-Sheet 1 FIG! INVENTOR JACK .5. VAUGHN BY l vi ORNEY Oct. 19, 1965J. 5. VAUGHN AXIAL PISTON TYPE IMPULSE TOOL 4 Sheets-Sheet 2 OriginalFiled Dec. 12, 1962 2 E m m l m y QW w L AM EM Ak A M87 B I W 7 m D, H 61i 6 V v H lsk INVENTOFZ JACK S. l4U6H/V BY W ATTORNEY Oct. 19, 1965 J.5. VAUGHN 3312,29

AXIAL PISTON TYPE IMPULSE TOOL Original Filed Dec. 12, 1962 4Sheets-Sheet 3 F |e| C I64 F E j FIG. 5

INVENTOK JACK S. Vfil/GH/V Oct 1 1965 J. s. VAUGHN 3,232,295

AXIAL PISTON TYPE IMPULSE TOOL Original Filed Dec. 12, 1962 4Sheets-Sheet 4 INVENTUE JAG/f 5. VAUGHN ATTORNEY United States Patent 12Claims. (Cl. 6426) The present invention relates to impulse tools of thetype disclosed in US. Patent No. 3,116,617 issued January 7, 1964, to D.K. Skoog and in US. patent application Serial No. 285,160 filed March18, 1963, by D. K. Skoog, and more particularly to an improved impulsetool of axial piston type. This application is a divisional applicationof US. patent application Serial No. 244,151 filed December 12, 1962, byD. K. Skoog et a1.

Heretofore, conventional portable, power operated tools for drivingnuts, bolts and screws or for applying a torque to other objects havebeen of the stall, clutch and impact type. While the stall type andclutch type tools give satisfactory torque control in most applications,these types are larger and hence heavier than the impact type tool.Further the stall type and clutch type tools are slower in operationthan the impact type tool. In addition the stall type and clutch typetools provide an undesirable torque reaction to the operator, whichtorque reaction is not present in a tool of the impact type.

In the impact type of tool the kinetic energy of the rotary hammer (oflarge mass) is transferred to the spindle (of relatively lower mass) bya collision between the jaws of the hammer and the spindle. Theseconventional impact tools have several limitations. First the rigid jawsof the hammer and the similar jaws of the spindle are relatively lightin order to satisfy the demand of the fabricating industries for a lightportable tool. However the forces between the jaws of the hammer and thejaws of the spindle are very high during the time of im pacttherebetween, with resultant breakage or failure of such jaws and ashorter service life than in other conventional power tools, such asthose of the stall or clutch types. Secondly, with these conventionalimpact tools it is very difficult to control or limit the final torqueon a threaded fastener to a final predetermined value withinsatisfactory limits of accuracy. Further the impact tools are difiicultto manufacture because of their complicated structure and are rathernoisy in their operation.

It is the general object of the present invention to avoid and overcomethe foregoing and other difficulties of and objections to prior artpractices by the provision of an improved tool of the impulse type whichtool has all of the advantages of the stall type, clutch type and impacttype tools and none of the disadvantages thereof.

A further object of the present invention is the provision of an impulsetype tool which operates in a fluid at low force levels with resultantminimum wear and attendant longer service life than conventional impacttools.

Another object of the present invention is the provision of an impulsetool which is operable to control the final torque on a threadedfastener accurately and precisely within predetermined limits.

Still another object of the present invention is the provision of animpulse tool which, because of the simplicity of its structure, is easyto manufacture.

Yet another object of the present invention is the provision of animpulse tool which provides relatively quiet operation as compared to animpact tool.

A further object of the present invention is the provision of animproved tool of the impulse type, the major elements of which tool actto seal dynamically or at high velocity and function as a valvestatically or at low velocity.

A still further object of the present invention is the provision of animpulse tool which is lighter in weight and faster in operation than thetools of the stall type and clutch type.

A further object of the present invention is the provision of an impulsetool which is operable to apply a torque or a series of impulses at anangle with respect to the longitudinal axis of the impulse tool.

A yet further object of the present invention is to provide an axialmovement type impulse tool which is simple in structure, easy tomanufacture and has a long operative life.

For a better understanding of the present invention reference should behad to the accompanying drawings, wherein like numerals of referenceindicate similar parts throughout the several views and wherein:

FIG. 1 is a side elevational view of the improved tool of the impulsetype, shown in engagement with a threaded fastener and with a stationarycasing means shown in vertical section;

FIG. 2 is a diagrammatic development view of a cam surface on thespindle;

FIG. 3 is a vertical sectional view of the impulse tool showing thehousing means as the driven member and before impulse;

FIG. 4 is a vertical sectional view along the line 44 of FIG. 2 in thedirection of the arrows;

FIG. 5 is a side elevational view of the spindle and spindle cam;

FIG. 6 is a View similar to FIG. 19 showing the cavity blocked off andafter impulse;

FIG. 7 is a side elevational view along the line 77 of FIG. 6 in thedirection of the arrows;

FIG. 8 is a view similar to FIG. 2 of an alternative embodiment;

FIG. 9 is a view similar to FIG. 7 of the alternative embodiment;

FIG. 9a is a view similar to FIG. 3 showing the spindle means connectedto the drive means and the housing means connected to the square drivefor the socket fastener;

FIG. 9b is a view similar to FIGS. 3, 9a showing the pressure reliefmeans and the blade slot in the spindle means, with the cam carried bythe housing means and with the housing means as the driven element.

The aforesaid objects of the present invention and other objects whichwill become apparent as the description proceeds are achieved byproviding an impulse tool for applying a predetermined torque to anobject. This impulse tool comprises housing means provided with a cavityadapted to contain a fluid, a spindle means rotatable in the cavity andin the fluid, and drive means connected one of the housing means andspindle means for impulsing the other which is connected to the object.One of the housing means and the spindle means is provided with arecess. Blade means are reciprocable in the recess and are provided withfluid bypass means in communication with the cavity on both sides of theblade means. Cam means are in the other of the housing means and thespindle means and are engageable with the blade means. Peak means are onthe cam means in engagement with the one. The cam means are operativeduring a relatively small portion of each revolution of the relativerotary movement to move the fluid bypass means into the recess. Theblade means and the cam means and the peak means and the one areoperable during the relatively small portion to seal off the cavity intoa high pressure portion thereby applying a torque to the object.

The axial movement type impulse tool has a reciprocable blade means inthe housing means. Spindle cam means is rotatable in the housing meansand in the fluid by means of the impulse.

While the impulse tool of the present invention may be advantageouslyemployed for applying a torque to objects and as a source of fluidimpulses in general, the impulse tool of the present invention isparticularly adapted for use in conjunction with applying a torque to athreaded fastener and hence it has been so illustrated and will be sodescribed.

With specific reference to the form of the present invention illustratedin the drawings, and referring particularly to FIG. 1, the impulse toolof the present invention for applying torque to a nut N on bolt S bymeans of socket 25 is indicated generally by the reference letter T.

As shown in FIG. 1 this impulse tool T has a housing means A providedwith a cavity 2k A adapted to contain a fluid, such as oil F.

FIGS. 2-9, 9a-9b In this embodiment blade means, such as the blade 161(FIGS. 2-9) is reciprocable in housing means A such as the inner housing160. Spindle means, such as the spindle cam 164 (FIGS. 26), on thespindle shaft 16k (FIGS. 3, 5, 6) is rotatable in the inner housing 160and in the oil F by the impulse.

The inner housing 160 is rotated by the output shaft 33k (FIGS. 3, 6) ofan air motor D (FIG. 1) in the direction of the arrow (FIGS. 3, 6) andis provided with a cavity 2k (FIGS. 2, 3, 6). The blade 161 isreciprocable in a longitudinal slot 162 (FIGS. 2, 3, 6) in the innerhousing 160.

As the inner housing 160 carrying blade 161 in slot 162 (FIGS. 2, 3)rotates from the position shown in FIG. 3 to the position shown in FIG.6, the blade 161 encountered the bottom B (FIGS. 2, 6) and rides up thespindle cam 164 thereby causing movement of the blade 161 toward the topof the slot 162 (as viewed in FIG. 6) and compression of the oil F inthe slot 162. At block-off point C (FIG. 2) the by-pass holes 166 (FIGS.2,3, 6) in the blade 161 have moved behind the face of the cavity 2kinto the slot 162 (FIG. 6).

Further rotation of the blade 161 between block-off point C7 and thepeak D (FIGS. 2-6) of the cam 164 through the angle B (FIG. 4)compresses the oil F entrapped therebetween in high pressure section HPwhich high pressure portion HP couples the spindle cam'164 and blade 161and thereby resulting in an impulse to (and rotation of) the spindle cam164, the spindle k and spindle shaft 16k. This fluid coupling or highpres sure portion HP is sealed by the blade 161 against the cam 164 andby the peak D of the cam 164 against the inner housing 160.

One impulse occurs during each revolution of the inner housing 160.However, by the use of multiple cams 164 (not shown) on the face of thespindle 15k multiple impulses may be obtained.

Leakage around the blade 161 (FIG. 2) balances the oil pressure in high.pressure portion HP and in slot 162.

To provide pressure relief means at predetermined torque, a relief valve168 is connected to the slot 162 (FIGS. 2, 3, 6).

,Referring to FIGS. 8 and 9 the by-pass holes 166 (FIGS. 2-3, 6-7) maybe eliminated and the pressure relief means may comprise a relief valve168a carried by the rotation inner housing 160 and connected by lines169a and 16919 disposed about the slot 162 and communicating with thecavity 2k. Leakage around the blade 161 in slot 162 permitsreciprocating movement of the blade 161 in the slot 162.

As shown in FIG. 9a the spindle means B may be connected to the outputshaft 33k of a drive means, such as an air motor D (FIG. 1), as thedriven member and the housing meansA is connected by means of its hous-4 ing shaft 167 to the square drive 16a for the fastener socket.

Referring now to FIG. 9b it will be understood by those skilled in theart that alternatively the pressure relief means, (Le, a relief valve168 and the blade slot 162 may be contained in the spindle means B andthat the cam 164 may be carried by the housing means A which is drivenby means of the output shaft 33k of an air motor D (FIG. 1).

It will be recognized by those skilled in the art that the objects ofthe present invention have been achieved by the provision of an impulsetool which applies a force, namely oil pressure, on the spindle bladeand spindle for a short time (namely during the dynamic sealing portionof the operating cycle of the impulse tool) thus providing operation ina fluid at low force levels with resultant minimum wear and attendantlonger service life than conventional impact tools.

The impulse tool of the present invention is operable to control thefinal torque on a threaded fastener accurately and precisely withinpredetermined practical limits. Further, because of the simplicity ofits structure, the impulse tool is easy and economical to manufacture.In addition, the impulse tool provides relatively quiet operation ascompared wtih conventional impact tools. The impulse tool acts as a sealdynamically and as a valve statically; has all of the advantages of thestall type, clutch type and impact type tools and none of thedisadvantages thereof; is lighter in weight and faster in operation thanthe tools of the stall type and clutch type.

Further an axial movement type impulse tool has been provided which hasa long operative life, is simple in structure and is hence easy tomanufacture.

While in accordance with the patent statutes one best known embodimentand alternative embodiments of the present invention has beenillustrated and described in detail, it is to be particularly understoodthat the invention is not limited thereto or thereby.

I claim:

1. An impulse tool for applying a torque to an object, said impulse toolcomprising:

(a) housing means provided with a cavity for sealingly containing afluid,

(b) spindle means in said cavity and in said fluid,

(c) drive means operatively associated with one of said housing meansand said spindle means for causing relative rotary movement between saidhousing means and said spindle means,

((1) the other of said housing means and said spindle means beingadapted to engage said object,

(e) one of said housing means and said spindle means being provided witha recess,

(f) blade means reciprocable in said recess and provided with fluidbypass means in communication with said cavity on both sides on saidblade means,

(g) cam means on the other of said housing means and said spindle meansand engageable with said blade means,

(h) peak means on said cam means in engagement With said one,

(i) said cam means being operative during a relatively small portion ofeach. revolution of said relative rotary movement to move said fluidbypass means into said recess,

(j). said blade means and said cam means and said peak means and saidone being operable during said relatively small portion to seal off saidcavity into a high pressure portion thereby applying a torque to saidobject.

2. The impulse tool recited in claim 1 wherein said drive means isconnected to said spindle means.

3. The impulse tool recited in claim 1 wherein said drive means isconnected to said housing means.

4. The impulse tool recited in claim 1 wherein said housing means isprovided with said recess.

5. The impulse tool recited in claim 1 wherein said spindle means isprovided with said recess.

6. The impulse tool recited in claim 1 wherein said fluid bypass meanscomprises a bypass hole through said blade means. 5

7. An impulse tool for applying a torque to an object comprising:

(a) housing means provided wtih a cavity for sealingly containing afluid,

(b) spindle means in said cavity and in said fluid,

(c) drive means operatively associated with one of said housing meansand said spindle means for causing relative rotary movement between saidhousing means and said spindle means,

(d) the other of said housing means and said spindle 15 means beingadapted to engage said object,

(e) one of said housing means and said spindle means being provided witha recess,

(f) blade means reciprocable in said recess and provided with a fluidleakage means in communication 20 with said cavity on both sides of saidblade means,

(g) cam means on the other of said housing means and said spindle meansand engageable with said blade means,

(h) peak means on said cam means in engagement with said one,

(i) said cam means being operative during a relatively BROUGHTON G.DURHAM, Primary Examiner. FRANK SUSKO, Examiner.

small portion of each revolution of said relative rotary movement tomove said cam means into said recess to decrease said fluid leakagemeans,

(i) said blade means and said cam means and said peak means and said onebeing operable during said relatively small portion to seal otf saidcavity into a high pressure portion thereby applying a torque to saidobject.

8. The impulse tool recited in claim 7 wherein said 10 drive means isconnected to said spindle means.

9. The impulse tool recited in claim 7 wherein said drive means isconnected to said housing means.

10. The impulse tool recited in claim 7 wherein said housing means isprovided with said recess.

11. The impulse tool recited in claim 7 wherein said spindle means isprovided with said recess.

12. The impulse tool recited in claim 7 wherein said fluid leakage meanscomprises the clearance between said recess and said blade means.

References Cited by the Examiner UNITED STATES PATENTS 8/51 Ramsey192--58 1/64 Skoog 6426

1. AN IMPULSE TOOL FOR APPLYING A TORQUE TO AN OBJECT, SAID IMPULSE TOOLCOMRPISING: (A) HOUSING MEANS PROVIDED WITH A CAVITY FOR SEALINGLYCONTAINING A FLUID, (B) SPINDLE MEANS IN SAID CAVITY AND IN SAID FLUID,(C) DRIVE MEANS OPERATIVELY ASSOCIATED WITH ONE OF SAID HOUSING MEANSAND SAID SPINDLE MEANS FOR CAUSING RELATIVE ROTARY MOVEMENT BETWEEN SAIDHOUSING MEANS AND SAID SPINDLE MEANS, (D) THE OTHER OF SAID HOUSINGMEANS AND SAID SPINDLE MEANS BEING ADAPTED TO ENGAGE SAID OBJECT, (E)ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS BEING PROVIDED WITH ARECESS, (F) BLADE MEANS RECIPROCABLE IN SAID RECESS AND PROVIDED WITHFLUID BYPASS MEANS IN COMMUNICATION WITH SAID CAVITY ON BOTH SIDES ONSAID BLADE MEANS, (G) CAM MEANS ON THE OTHER OF SAID HOUSING MEANS ANDSAID SPINDLE MEANS AND ENGAGEABLE WITH SAID BLADE MEANS, (H) PEAK MEANSON SAID CAM MEANS IN ENGAGEMENT WITH SAID ONE, (I) SAID CAM MEANS BEINGOPERATIVE DURING A RELATIVELY SMALL PORTION OF EACH REVOLUTION OF SAIDRELATIVE ROTARY MOVEMENT TO MOVE SAID FLUID BYPASS MEANS INTO SAIDRECESS, (J) SAID BLADE MEANS AND SAID CAM MEANS AND SAID PEAK MEANS ANDSAID ONE BEING OPERABLE DURING SAID RELATIVELY SMALL PORTION TO SEAL OFFSAID CAVITY INTO A HIGH PRESSURE PORTION THEREBY APPLYING A TORQUE TOSAID OBJECT.